The thing I liked about Twitter was following:

• Writers
• Academics and scientists
• Artists

Basically, following INTERESTING content creators was my jam. As someone who never made it all the way through college, but is basically a big nerd anyhow, Twitter was basically my only exposure to academic nerds who had a lot of interesting things to talk about. YouTube makes you sit through videos (which is nice sometimes, but too long other times for a fast reader like me), and people's websites are never updated, and science papers I may or may not have the background to follow, but on Twitter, even academics had to learn how to convey their ideas in an understandable concise way. It was able to expose me to knowledge and social circles I never would have crossed in real life.

Reddit (now Lemmy) gives the same fix, but from anonymous people who contribute knowledge to a general pool instead of being a singular person to follow for a given topic.